1. Field of the Invention
The invention relates to an infrared radiator arrangement for a gas analysis device including a radiator housing, a plate-shaped ceramic body arranged in the interior of the radiator housing and a structured heat resistant layer applied on the plate-shaped ceramic body housing and, where the interior of the radiation housing is closed off on one side by a radiation-transmissive window.
2. Description of the Related Art
Resistance radiators are usually used as broadband radiation source for infrared gas analysis, where a coiled filament is arranged in a reflector housing that is closed off by a radiation-transmissive window, e.g., a CaF2-IR window. Here, the housing is filled with a protective gas, e.g., N2, in order to avoid chemical reactions between the coiled filament and the surrounding air. However, it is also possible to use different gases, e.g., O2, in order to produce a protective layer, e.g., an oxide layer, on the coiled filament.
Planar radiation sources are known, where a structured heat resistant layer using a thick or thin film technique is formed directly on a radiation-transmissive window (e.g., U.S. Pat. No. 4,620,104) or on a ceramic body arranged in a radiator housing (e.g., DE1936245, DE4420340).
In the arrangement disclosed in DE1936245, a heat resistant layer is deposited on the front side of a rectangular ceramic platelet, on the back side of which a platinum resistance thermometer is deposited, cemented with putty, or sintered. The ceramic platelet is supported by connectors for the heat resistant layer and the platinum resistance thermometer, which lead outward through the rear wall of the radiator housing.
In the arrangement disclosed in DE4420340, a heat resistant layer using a thick film technique is printed onto the front side of a likewise rectangular AlN substrate in a snaking manner as a paste, e.g., Pt-paste, and is subsequently baked. A thermosensor comprising a thermocouple is applied on the rear side of the ceramic substrate. DE4420340 does not disclose precisely how the ceramic substrate is mounted in the radiator housing.